1. Field
One or more embodiments of the present invention relate to a polymer electrolyte membrane, a membrane electrode assembly, and a fuel cell including the polymer electrolyte membrane.
2. Description of the Related Art
Typical examples of a fuel cell are a polymer electrolyte membrane fuel cell (PEMFC), a direct methanol fuel cell (DMFC), a phosphoric acid fuel cell (PAFC), a molten carbonate fuel cell (MCFC), or a solid oxide fuel cell (SOFC).
The PEMFC is recognized as a system that has high efficiency, high power density, low driving temperature, and environmentally friendly properties, and can potentially replace conventional energy conversion devices.
The PEMFC generally includes a membrane electrode assembly (MEA) including an anode, a cathode, and a polymer electrolyte membrane between the anode and the cathode.
As a polymer electrolyte membrane used in a PEMFC, a fluorinated polymer electrolyte membrane and a hydrocarbon-based polymer electrolyte membrane are generally used. The fluorinated polymer electrolyte membrane has good ion conductivity, chemical stability, and ion selectivity. However, the fluorinated polymer electrolyte membrane is expensive, has high hydrogen gas permeability, and has a reduced efficiency at a temperature at or above 80° C.